The invention relates to a wheelchair platform, particularly to a compact wheelchair platform.
Wheelchair platforms are used by medical personnel, for example in dental surgeries, to assist in the clinical treatment of wheelchair users. Typically a wheelchair is wheeled onto the platform as far as a back wall will allow and the wheelchair brake is applied. A backrest and headrest assembly supports the person in the wheelchair. The platform can be tilted backwards to set the patient's head, or feet, into a good treatment position for, say, dental or podiatry procedures. The patient remains in his own wheelchair at all times, eliminating manual handling and hoisting.
Wheelchair platforms may also be used for facial work as part of a medical or cosmetic procedure. They may even be used to tilt back a wheelchair user to facilitate hair washing and hairdressing.
An example of a wheelchair platform optimally designed for clinical use is the Full Function Wheelchair Platform available from Design Specific Limited. This wheelchair platform provides a rise and fall function in addition to a tilting function so the wheelchair user can be placed at the perfect height for e.g. a medical professional to work in comfort, while also ensuring patient comfort at all times. Because the platform is installed into the floor of a room it may not be suitable for every situation.
There is also available from Design Specific Limited a Standard Wheelchair Platform which does not require permanent installation and which can tilt a wheelchair back to a maximum angle of 45°. This typically puts a patient's head at a height of 80 cm from the floor, which is low enough for normal seated working. Although it may be desirable in some circumstances for the patient to be tilted further back, the angle of tilt is limited to 45° so as to ensure the stability of the platform. In this situation a clinician may instead use a pump-up stool to attain the required working height above the patient.
The stability of existing powered wheelchair platforms when fully reclined is always an issue. All the currently available powered wheelchair platforms have a support base to which the tilting platform is operatively connected. This support base is often called a chassis. The chassis provides a large stabilising footprint on the floor and helps to ensure that the overall centre of gravity is always towards the front of the wheelchair, even when it is tilted back. Stabilising feet may also be deployed behind the platform.
In the Diaco® dental chair, stabilisation is further ensured by disposing the pivot means for the platform rearward of the back wall of the platform and spaced apart from it. In this product the hydraulic rams which lift the platform are mounted between the chassis and the platform, behind the back wall of the platform and forward of the pivot means. Even when the platform is tilted back to the maximum angle of 50° from the chassis, the centre of gravity of the wheelchair and user remains far forward of the pivot axis. A retractable stabilizer arm rearward of the pivot axis can be lowered into contact with the ground for additional stabilisation, especially at large tilting angles.
While stabilising arms, and feet rearward of the platform may be retractable, the Applicant has realised that a stabilising chassis beneath the wheelchair platform can represent a large and heavy structure which takes up space and can limit the transportability of the apparatus. There remain issues with the size and weight of wheelchair platforms. Particularly in clinical environments, space can be at a premium.